Rear defrost

Yesterday my rear window was fogged, and just noticed it does not work. The light appears on the button when pressed, I do not have an owners manual, and could not find what fuse shoukd be. I did check the higher Amp fuses, they all look good.
Has anyone experienced similar situation? I did google, but couldnt find anything. Looks like troubleshooting starts with removing the plastic trim around the back hatch.


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check resistance of the defroster element. also not sure if there is a temp threshold for activation.

Vpstang said:

Yesterday my rear window was fogged, and just noticed it does not work. The light appears on the button when pressed, I do not have an owners manual, and could not find what fuse shoukd be. I did check the higher Amp fuses, they all look good.
Has anyone experienced similar situation? I did google, but couldnt find anything. Looks like troubleshooting starts with removing the plastic trim around the back hatch.

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The fuse layout isn't in my manual for my 2012, so you aren't missing anything there.
Usually, the defroster is controlled by a relay - the switch sends current to close the heavy duty relay contacts, and that provides the power to the defroster.
(..relays are cheaper than switches that can handle lots of amps, so a small dash switch controls a relay...)
My guess is that if the light in the switch goes on, you are sending power to the relay.
If you don't have power at the back window (check for 12v between the connector tabs and ground) then I'd suspect the relay. A relay shouldn't be too expensive; they plug in .
If you do have power at the window connector, then the problem is in the window grid.

My 90s VWs have been plagued with broken wires (insulation gets stiff and fractures the wire) and I've heard of broken wires in the rubber flex wiring connector to the hatch. I thought VW had cured that problem by the time our JSWs came along.

Thanks for the help. Im going home this weekend, ill bring my multimeter back with me and dig into this.
Makes sense its a relay, ill do some testing and get back to post the fix.


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Over the weekend I pulled the hatch trim and checked voltages. Got nothing at the terminal and wires. The fuses are good, next step is replacing the relay, need to hit it an autozone and grab one


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The operating lite switch shound basically say your getting power & ground to the switch. There was no note if you checked the grid for power/voltage then if not Id 1st check the grid connecting wires for power, then grid for continuity. That will give you direction to repair the grid or wire or trace back for electrical dead end.

Tonight before coming to work I poked around some more, found the issue, the passenger side connection has broken off, thats the issue. Time to find a cordless soldiering
iron. Lol


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This morning I was able to test the rear defroster, my quick soldier of the passenger tab back to the wire grid worked good. Nice being able to see out if ghe back window. Thanks for all help [emoji1360]


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